Dr Nial Moores, Birds Korea, June 25th 2025
Since 2009, Birds Korea, with a few annotated exceptions, has been following the taxonomic and nomenclature recommendations made for the International Ornithologists’ Union (formerly known as the IOC) in our publications and checklists. In more recent years, several of us have also become active eBirders (both as reviewers and as users), and have worked on Merlin.
As such, Birds Korea will now follow the AviList, the world’s first checklist to unify the opinions of the IOC with eBird and several other bird organisations.
As announced on various English-language platforms on June 11th:
“AviList is a brand-new, complete global checklist of species and taxonomy. Containing 11,131 species, 19,879 subspecies, 2,376 genera, 252 families and 46 orders, it brings together the latest global thinking on what constitutes a species and shakes up our understanding of the avian world.
Until now, ornithologists, conservationists and birders have used a selection of global checklists, each with its own reasoning on what constitutes a specific species of bird. AviList’s unified view has been developed by the Working Group on Avian Checklists, containing representatives from BirdLife International, the Cornell Lab of Ornithology, the American Ornithological Society, the International Ornithologists’ Union IOU) and Avibase. The new checklist will replace the International Ornithological Community and Clements lists, and will be updated annually” (BirdLife International, June 11th 2025).
This mammoth project is expected, at least in the mid- to long-term, to benefit bird conservation as well as birders, because as noted by Marshall Iliff (known to many birders in Korea because of his role in eBird and his time at Ulsan), “In trying to protect birds at a global scale, it is important to ensure that everyone is talking the same language and the data match… laws and treaties used to protect species don’t work as well when there isn’t consensus on species names” (Cornell Lab, June 11th 2025).
As a representative of a Korean conservation NGO, I agree completely with this sentiment. One example should suffice: “Bean Goose” is understood to comprise two species by the IOC and in the 2025 AviList (and therefore also in Birds Korea Checklists), Tundra Bean Goose Anser serrirostris 큰기러기 and Taiga Bean Goose Anser fabalis 큰부리큰기러기. However, “Bean Goose” is listed as a single species within the ROK by e.g., the Ministry of Environment, and also by Wetlands International in their Waterbirds Population Estimates, and until now also by BirdLife International, who assessed “Bean Goose” as Least Concern. In the ROK, this means that Winter Census data cannot be used to improve our understanding of the different national population trends of the two species, as they are not listed separately. In addition, because of the recent rapid increase in the number of Tundra Bean Goose here in Korea during migration it seems possible that the “Bean Goose” might soon lose its national assessment as “Threatened”. However, at the very same time that the Tundra Bean Goose is growing in number, the Eastern Taiga Bean Goose Anser (fabalis) middendorffii 큰부리큰기러기 is fast-declining in their Russian breeding grounds (Degtyarev 2024), and appears to be declining in the southeast of the nation.
Looking ahead, the pooling of expertise and resources in support of the AviList should happily also start to reduce what has increasingly felt rather chaotic for those trying to keep up, “with three major global checklists independently assessing taxonomic revisions from one to four times a year“.
The process of unifying checklists while improving the scientific base needs to continue, of course, as researchers and birders make new discoveries. As proposed, the AviList team will therefore try to develop regional teams of experts, will start to look more closely at subspecies and will publish updates annually. And just like the IOC Checklist managers, who have done a truly superb job over the past decade and more (our sincere thanks to them), the AviList team states that they will stay open to informed input. This, we hope, will include using eBird records to refine some of the distribution notes provided in their full version excel sheet (one example: the distribution of Japanese Wagtail Motacilla grandis 검은등할미새, a widespread breeding species in Korea, is given in error as, “breeds Japanese Islands; winters to China, Korea, and Taiwan”).
In the here-and-now, though, how will the 2025 Avilist checklist affect eBirders in Korea and those using Birds Korea Checklists?
First, the order in which species are listed will be different. Revision for the 2025 Birds Korea Checklist, to make it compatible with AviList, required at least 155 changes from the sequence used in the 2024 list. Some of these changes will be obvious, with e.g., the Cotton Pygmy Goose 쇠솜털오리 now right at the top of the list, instead of listed 22nd toward the middle of the Anatidae; and the Greater Flamingo 큰홍학, has been moved up – to sit (or stand tall!) between Japanese Quail 메추라기 and Little Grebe 논병아리. Other such changes might be rather less obvious, but will likely “feel” odd. Most remarkable perhaps is the near-complete rearrangement of the buntings – with Yellow-throated Bunting 노랑턱멧새 now listed first, oddly followed next by the strikingly different Ochre-rumped Bunting 쇠검은머리쑥새.
Second, two species in the earlier Birds Korea Checklists and on eBird are demoted to subspecies. Arctic Redpoll 쇠홍방울새 has been subsumed into the all-encompassing Redpoll 홍방울새 (a change made less than a year ago by eBird); and, Eurasian Teal Anas crecca 쇠오리 and Green-winged Teal Anas carolinensis 미국쇠오리, only found in Korea as an exciting vagrant, have now been lumped together confusingly under the name of Green-winged Teal Anas crecca (쇠오리). To reduce this confusion, the next Birds Korea Checklist will likely use the name Common Teal instead, with the existing Korean names still applied to the two subspecies.
Third, (please take special note all eBird users!), although the changes will of course not affect Korean names, a couple of species will effectively disappear and reappear with very different English and scientific names. Striated Heron Butorides striata (검은댕기해오라기) is now listed by AviList 2025 as Little Heron Butorides atricapilla; and the only breeding stonechat 검은딱새 (variously known in English as Stejneger’s Stonechat and then as Amur Stonechat) reverts back to being the stejnegeri subspecies of Siberian Stonechat Saxicola maurus…These changes follow on from splits that were already recognised by the IOC, and were included in earlier Birds Korea Checklists, such as the split of Lesser Sand Plover Charadrius mongolus 왕눈물떼새 (more recently known as Mongolian Plover) into Tibetan Sand Plover Anarhynchus atrifrons (only one record known to us in Korea) and Siberian Sand Plover Anarhynchus mongolus, with the currently very unconvincing and quite misleading Korean names of 왕눈물떼새 and 몽골왕눈물떼새 respectively. Recommendations for better Korean names are urgently needed please!
Fourth, while Mongolian Gull Larus mongolicus 한국재갈매기 is formally recognised as a full species (finally!), Taimyr Gull 줄무늬노랑발갈매기 still remains out in the taxonomic wilderness. According to the 2025 AviList distribution note, all records of taimyrensis refer to the heuglini subspecies of Lesser Black-backed Gull 검은등갈매기 (another unsatisfactory Korean language name) which, “breeds tundra from Kola Peninsula (northwestern Russia) to Yamal Peninsula (north-central Siberia); winters from Middle East southward to east Africa and eastward to India, eastern China, and South Korea”. Going forward, presumably eBirders will now have to enter all taimyrensis under Larus fuscus heuglini. How to reconcile this with recent tracking of (nominate) Heuglin’s Gull from the breeding grounds to East Africa (as expected) and the extreme rarity of claims in the Yellow Sea of nominate heuglini but the presence of flocks of taimyrensis?
Fifth and finally, although a couple of our preferred English names have been adopted (e.g., Black Wood Pigeon and Black Paradise Flycatcher) – thanks to the input of Marshall Iliff following our post- many of the same rather misleading names remain, such as Japanese Thrush instead of our preferred Grey Thrush. As before, in such cases Birds Korea will continue to use our preferred names in our checklist, with some annotation or highlighting to show their difference from AviList.
For those who use the Birds Korea checklist: if time can be found, we will publish an updated, simple AviList-based 2025 Birds Korea Checklist this summer and a more fully annotated list this winter – on what we hope will be a new Birds Korea website. Our Checklist currently treats about 617 species, with at least 573 to be listed in Category One, as considered to be adequately documented and fully naturally occurring in the ROK since 2000. The most recent additions comprise Little Gull Hydrocoloeus minutus 꼬마갈매기 on the basis of one in Gangneung in December 2023; Red-tailed Shrike Lanius phoenicuroides (Gimpo, Gyeonggi Province, December 2024 – March 2025); and presumably Pied Bushchat Saxicola caprata (Gureupdo, Incheon, April 2025).
The national first record of the presumed ship-assisted Great-tailed Grackle (Busan, October 2024? to?) will be listed in Category 5, while the Green-backed Tit Parus monticolus on Shinjindo, Taean County on April 16th 2025 while clearly identified correctly, raises some of the same questions as the Oriental Magpie-Robin Copsychus saularis 까치울새 on Eocheong a couple of years ago. Gosler et al. (2024) in Birds of the World describe Green-backed Tit as “Largely resident or short-distance altitudinal migrant”, wintering in Sichuan from 100 up to 3050 masl; and the closest records shown on eBird are in Shanxi and Henan, more than 1,200 km from Korea – with most of that distance comprising near treeless flat plains and open sea.
Are more-or-less sedentary species like this really able to cross the Yellow Sea under their own power? And if not, what are their origins? How to treat such records if a pattern of out of range records of such species begins to emerge? Clearly, a national committee willing to communicate regionally is increasingly needed to decide upon records like this – a process that the AviList might help support, in the same way that eBird does now. For example, in the case of the near sedentary Oriental Magpie-Robin (currently listed in Category 5), we learned this year from Qingdao-based birder Xuky (徐克阳 ) that a pair raised two young there in 2024, and that there are other records on the Shandong Peninsula (in lit. January 2025). Even eBird now shows a record from Japan. Are these naturally-occurring off-course migrants? Or were they ship-assisted somehow (perhaps as escapees from passing boats)? Or might they perhaps originate from merit releases conducted far out of their natural range ?
Already, we know that species earlier thought not to undergo long migrations like Light-vented Bulbul 검은이마직박구리 and Yellow-bellied Tit 노랑배진박새, do cross the Yellow Sea regularly, and both are clearly expanding their ranges rapidly to the north and east. Perhaps additional (previously) near-sedentary species from southern and central China like Oriental Magpie-Robin and Green-backed Tit will also be found to be shifting their ranges north and east in response to increasingly severe climate breakdown…Only time, and sharing of information, will tell.
For more on AviList, please see here.
References
Degtyarev, V. G. 2024. Distribution, trends and threats to Eastern Taiga Bean Goose Anser fabalis middendorffii in the River Lena basin, East Siberia. Wildfowl 74: 23–39.
Gosler, A., P. Clement, P. Pyle, and G. M. Kirwan (2024). Green-backed Tit (Parus monticolus), version 1.1. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.grbtit1.01.1
